A 65-year-old man who opposes Barack Obama's plans for healthcare reform had one of his fingers bitten off during a pro-reform rally organised by the liberal political action group MoveOn.org.

After 100 protesters supporting a healthcare overhaul assembled for a vigil in Thousand Oaks, California yesterday, a group of people who opposed reform showed up.

A confrontation ensued between a man who supported healthcare reform and one of the members of the anti-reform group, police said.

The two men yelled at each other and then got into a fist fight. As the brawl escalated, the pro-reform protester bit a finger off of the 65-year-old.

The injured man walked to a nearby hospital where his finger was reattached. A hospital spokeswoman said the man had Medicare, the US government-run insurance programme for older citizens.

A MoveOn spokeswoman expressed regret for the incident and said the organisation "condemns violence in all forms," according to Politico.

She said: "While we don't know if either party involved was a MoveOn member, we regret any violence that may have occurred yesterday, and we support the Ventura county sheriff's investigation into the situation."